Winding mechanism for back winding watch

ABSTRACT

A winding mechanism for watches particularly back winding watches in which a winding stem has a winding gear rotational thereon provided with ratchet teeth. The winding gear meshes with a ratchet gear at all times. A clutch gear is mounted for rotation with the winding stem and is axially slidable thereon. It is biased by a spring toward engagement with the ratchet teeth of the winding gear by means of a spring. The clutch gear is declutched when the winding stem is pulled out for a hand-setting operation. The clutch gear is engaged by an enlarged diameter portion of the winding stem lifting it so that it disengages from the ratchet teeth of the winding gear against the action of its biasing spring.

WINDING WATCH United States Patent 1 1 1 1 3,916,615 Maeda Nov. 4, 1975WINDING MECHANISM FOR BACK 2,412,493 12/1946 Carlstrom 58/68 PrimaryExaminerGeorge H. Miller, Jr. [75] Inventor. Katsutoshi Maeda, Tokyo,Japan Attorney Agent or Firm Robert E Bums; [73] Assignee: KabushikiKaisha Daini Seikosha, Emmanuel J. Lobato; Bruce L. Adams Japan 22Filed: Aug. 27, 1974 [57] ABSTRACT A winding mechanism for watchesparticularly back [21] Appl 500860 winding watches in which a windingstem has a winding gear rotational thereon provided with ratchet [30]Foreign Application P iority D t teeth. The winding gear meshes with aratchet gear at Aug. 28, 1973 Japan 48-96462 all times- A Clutch gear ismounted for rotation with the winding stem and is axially slidablethereon. It is 52 US. 01. 58/68 biased by a Spring toward engagementwith the ratchet 51 int. (31. G04B 27/04 teeth of the Winding gear bymeans 0f e SPthtg- The [58] Field of Search 58/63 67-69 eluteh gear isdeehttehed when the Winding Stem is pulled out for a hand-settingoperation. The clutch [56] References Cited gear is engaged by anenlarged diameter portion of the winding stem lifting it so that itdisengages from the UNITED STATES PATENTS ratchet teeth of the windinggear against the action of 644,381 2/1900 Voegelin 58/68 its biasingspring. 739,089 9/1903 Kuenzel 58/68 771,227 10/1904 Blane 58/68 5 l m 2Drawmg Figures l 1 l2 3 I ll 1 Ha I I l l e 7 1 1b 2a 2 I I ll! iii 7 iP l2 3 9 Ha i 1Q 1 5.1. 8a

FIG. 2 1

i lb I 2 Nb '2 J I All I I Q! I I 9 3 8a l 4 M I I] 11 H 1c 8 I I I IIIHill 7 L\ I\ l \1 WINDING MECHANISM FOR BACK WINDING WATCH BACKGROUND OFTHE INVENTION This invention relates generally to a winding mechanismfor a watch and more particularly to back winding watches and windingmechanisms therefore.

In conventional watches a winding gear is mounted on the winding stemand is engaged with a ratchet gear in a winding position of the windingcrown and stem. The winding gear is disengaged from the ratchet gearwhen the winding crown and stem are pulled axially to a hand-settingposition. Generally, in returning the winding stem from its hand-settingposition to its winding position trouble is encountered in coupling orengaging the winding gear with the ratchet gear teeth.

Another problem encountered in this kind of situation in conventionalwatches is that the winding crown cannot be rotated in a reversedirection when it is in its winding position.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a winding mechanism for watches and more particularly backwinding watches, wherein the winding gear is continuously meshing with aratchet gear thereby insuring continuous readiness for winding a watch.

Another object of the present invention is to provide the windingmechanism for a thin-type back winding watch having a winding crownwhich may be reversely rotated and generates a sound signal to preventdamage of the gears.

The watch winding mechanism in accordance with the invention has awinding stem mounted for rotation and movable axially from a windingfirst position to a hand-setting second position. A clutch gear ismounted coaxially with the winding gear and is axially slidable on thewinding stem for rotation therewith. Spring means constantly,resiliently biases the clutch gear axially of the winding stem in adirection for meshing with the driving gear clutch teeth. The springmeans allows the clutch gear to be displaced axially away from theclutch if the clutch gear is rotated by the winding stem in a directionopposite to the winding direction for winding the winding mechanism.Means are provided on the winding stem to displace the clutch gearaxially away from the winding gear against the biasing force of thespring means, when the winding stem is moved axially to its secondposition.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of thewinding mechanism in accordance with the invention will appear from thefollowing description of an example of the invention and the novelfeatures will be particularly pointed out in the appended claims anddrawings in which:

FIG. 1 is a fragmentary elevation view, partly in section, of a watchwith a watch winding mechanism according to the invention; and

FIG. 2 is a fragmentary elevation view, partly in section, of a secondwatch embodiment with a second embodiment of a winding mechanism inaccordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will befully described by way of two embodiments embodying the invention and inconnection with accompanying drawings. In FIG. 1 a winding stem 1 isrotationally and axially slidable in a watch structure. The winding stem1 is provided with a winding crown 2 secured to the winding stem 1 in aconventional manner and having a cylindrical portion 2a. The windingstem extends axially through openings in a casing member 3, a barrelbridge 4 and a plate 5. A round portion 1a thereof is rotatable in thebarrel bridge.

The watch is provided with a hand-setting mechanism for setting thehands, not shown, of the watch comprising a hand-setting or intermediategear 6 meshing with a gear train including a minute gear for setting thehands. The intermediate gear 6 is actuated by a transmission gear 7rotated by the winding stem 1 when it is in a hand-setting mode.

The winding mechanism according to the invention comprises a windinggear 8 mounted for rotation on the winding stem 1 and has ratchet teeth8a on an upper surface thereof with peripheral teeth meshing with aratchet gear 10 that is used for winding the winding spring in thewatch. The ratchet gear 10 is constantly in mesh with the winding gear8. The winding gear 8 is protected by a winding gear guard 9 secured onthe barrel bridge 4 and serves to control the axial movement of thewinding wheel or gear 8 as later described.

In order to wind the winding mechanism, the mechanism is provided with aclutch gear 11 mounted coaxially with the winding gear 8 and havingteeth for meshing with the ratchet teeth 8a of the winding gear. Theclutch gear 11 is mounted on a square or rectangular cross-sectionportion 1b of the winding stem 1 for rotation with the winding stem andto allow axial movement of the clutch gear relative the winding stem.The clutch gear 11 is biased by biasing spring 12 in a direction formeshing it with the clutch teeth of the winding gear. The spring 12 isdisposed within the cylindrical or tubular portion 2a of the crown 2.This reduces the thickness of the watch. When the crown and winding stemare in a position shown, a winding or first position is established inwhich the winding mechanism can be wound for winding the watch. In orderto set the hands of the watch, the crown 2 and winding stem 1 are pulledoutwardly and the transmission gear 7 is meshed or engaged with theintermediate hand-setting gear 6 for setting the hands. A collar 10lifts the clutch gear 11 from engagement with the winding gear 8vagainst the biasing force of the spring 12 so that rotation of the crownfor setting the hands does not affect the winding mechanism.

When the winding stem is in the position illustrated in FIG. 1 thewinding mechanism can be wound by rotating the winding stem into anangular position in which the clutch gear engages with the winding gearunder the control of its biasing spring and the winding mechanism isaccordingly wound. In the event that the winding crown is rotated in areverse direction the clutch gear teeth of the winding gear 8 cause theclutch gear 11 to move away axially from the winding gear against theresiliency of the spring 11 to prevent damage to the gears and windingmechanism. During the movement away from the clutch gear a sound signalis effected.

Moreover, when the winding crown 2 and winding stem are moved to thesecond position thereof, for setting the hands of the clock, the collar1c of the winding stem engages a stepped portion 11a of the clutchwheel. The clutch wheel or gear is moved against the resiliency of thespring 12. The winding gear guard .9 prevents the winding gear 8 frommoving with the winding stem in an axial direction wherebythe windinggear 8 is constantly kept in engagement with the ratchet gear 10 duringthe hand-setting operation. After the setting of the hands has takenplace, the crown 2 is returned to the position as shown in FIG. 1 andthe clutch gear 11 is biased by the spring 12 so that it again mesheswith the ratchet teeth 8a of the winding gear 8 whenever the gears arein angular phase for this engagement.

A second embodiment of the invention is illustrated in FIG. 2. In thisembodiment a winding stem 1' has a rectangular or square cross-sectionl'b and a crown not shown. It extends axially through a casing member,not shown, a barrel bridge 4 and a plate 5'. The winding stem 1 drives ahand-setting mechanism having a hand-setting or intermediate gear 6'which is driven by a transmission gear 7 mounted on the winding stem 1when it is moved to a hand winding position upwardly.

A winding mechanism is provided in. the present invention similarily tothe first embodiment. A winding gear 8' is rotationally mounted on thewinding stem and meshes continuously with a winding gear A clutch gear11 is provided and in this instance is disengaged from the winding gearby a shoulder 1d which engages a shoulder ll'a of the clutch gear when ahand-setting operation is effected. A guard plate 9' keeps the windinggear 8 meshing with the ratchet gear 10. The clutch gear 11 is in thisinstance biased by a plate spring 12 which has a portion biasing theclutch gear and is anchored as shown to the watch.

A hand-setting gear 6' meshes with a transmission gear during ahand-setting operation as described before as to, the first embodiment.

Thus provision is made in the present invention to eliminate theproblems heretofore mentioned with respect to conventional watches. Thecrown may be rotated in opposite directions without any problem.Moreover, it is possible to lessen the thickness of the watch becausethe spring 12 is housed in the-winding crown 2 or in a watch case asshown in FIG. 2. Shocks on the winding crown are absorbed by the windinggear 8 and the barrel bridge 4 by means of the flange 1c of the windingstem so that damage to the watch movement can be eliminated.

What I claim and desire to secure by Letters Patent 1. A windingmechanism comprising a winding stem mounted for rotation for winding awatch-winding mechanism in a winding first position and movable axiallyto a hand-setting second position for rotation for setting hand-settingmechanism, a winding crown mounting said winding stem for rotation andaxial movement, a winding gear mounted for rotation about said windingstem and having peripheral teeth and ratchet teeth, a ratchet gearmeshing with the peripheral teeth of said winding gear, a clutch gearmounted coaxially with said winding gear and axially slidable on saidwinding stem for rotation therewith, spring means housed in a spacedefined between said winding stem and said winding crown and constantlyresiliently biasing the clutch gear axially on said winding stem in adirection for meshing with said ratchet teeth of the winding gear andallowing said clutch gear to be displaced axially away from said windinggear when said crown is rotated in a direction opposite to a windingdirection for winding said winding mechanism, and means on said windingstem to displace said clutch gear axially away from said winding gearagainst a biasing force of said spring means when said winding stem ismoved axially from said first winding position to said hand-settingsecond position.

2. A winding mechanism according to claim I, including guard means forpreventing said winding gear from moving axially with said stern,whereby said winding gear and said ratchet gear mesh at all times.

3. In a watch, a winding stem mounted for rotation for winding awatch-winding mechanism in a winding first position and movable axiallyto a hand-setting second position for rotation for setting hand-settingmechanism, means mounting said winding stem for rotation and axialmovement, said winding mechanism comprising a winding gear mounted forrotation about said winding stem and having peripheral teeth and ratchetteeth, a ratchet gear meshing with the peripheral teeth of said windinggear, a clutch gear mounted coaxially with said winding gear axiallyslidable on said winding stem for rotation therewith; spring meansconstantly resiliently biasing the clutch gear axially on said windingstem in a direction for meshing with said driving gear clutch teeth andallowing said clutch gear to be displaced axially away from said clutchgear if said clutch gear is rotated by said winding system in adirection opposite to a winding direction for winding said windingmechanism, means on said winding stem to displace said clutch gearaxially away from said winding gear against a biasing force of saidspring means when said winding stem is moved axially to said secondposition thereof, and said means on said stem comprising a portionhaving a diameter defining a shoulder for engaging said clutch gear.

4. In a watch, a winding stem mounted for rotation for wind-ng awatch-winding mechanism in a winding first position and movable axiallyto a hand-setting second position for rotation for setting hand-settingmechanism, means mounting said winding stern for rotation and axialmovement, said winding mechanism comprising a winding gear mounted forrotation about said winding stem and having peripheral teeth and ratchetteeth, a ratchet gear meshing with the peripheral teeth of said windinggear, a clutch gear mounted coaxially with said winding gear axiallyslidable on said winding stem for rotation therewith, spring meansconstantly resiliently biasing the clutch gear axially on said windingstem in a direction for meshing with said driving gear clutch teeth andallowing said clutch gear to be displaced axially away from said clutchgear if said clutch gear is rotated by said winding system in adirection opposite to a winding direction for winding said windingmechanism, means on said winding stem to displace said clutch gearaxially away from said winding gear against a biasing force of saidspring means when said winding stem is moved axially to said secondposition thereof, and said means on said stem comprising a collar onsaid stem disposed on said stem for engaging said clutch gear.

5. In a watch, a winding stem mounted for rotation for winding awatch-winding mechanism in a winding first position and movable axiallyto a hand-setting second position for rotation for setting hand-settingmechanism; means mounting said winding stem for rotation displacedaxially away from said clutch gear if said clutch gear is rotated bysaid winding system in a direction opposite to a winding direction forwinding said winding mechanism, means on said winding stem to displacesaid clutch gear axially away from said winding gear against a biasingforce of said spring means when said winding stem is moved axially tosaid second position thereof, and said spring means comprising a springhoused in said crown.

1. A winding mechanism comprising a winding stem mounted for rotationfor winding a watch-winding mechanism in a winding first position andmovable axially to a hand-setting second position for rotation forsetting hand-setting mechanism, a winding crown mounting said windingstem for rotation and axial movement, a winding gear mounted forrotation about said winding stem and having peripheral teeth and ratchetteeth, a ratchet gear meshing with the peripheral teeth of said windinggear, a clutch gear mounted coaxially with said winding gear and axiallyslidable on said winding stem for rotation therewith, spring meanshoused in a space defined between said winding stem and said windingcrown and constantly resiliently biasing the clutch gear axially on saidwinding stem in a direction for meshing with said ratchet teeth of thewinding gear and allowing said clutch gear to be displaced axially awayfrom said winding gear when said crown is rotated in a directionopposite to a winding direction for winding said winding mechanism, andmeans on said winding stem to displace said clutch gear axially awayfrom said winding gear against a biasing force of said spring means whensaid winding stem is moved axially from said first winding position tosaid hand-setting second position.
 2. A winding mechanism according toclaim 1, including guard means for preventing said winding gear frommoving axially with said stem, whereby said winding gear and saidratchet gear mesh at all times.
 3. In a watch, a winding stem mountedfor rotation for winding a watch-winding mechanism in a winding firstposition and movable axially to a hAnd-setting second position forrotation for setting hand-setting mechanism, means mounting said windingstem for rotation and axial movement, said winding mechanism comprisinga winding gear mounted for rotation about said winding stem and havingperipheral teeth and ratchet teeth, a ratchet gear meshing with theperipheral teeth of said winding gear, a clutch gear mounted coaxiallywith said winding gear axially slidable on said winding stem forrotation therewith; spring means constantly resiliently biasing theclutch gear axially on said winding stem in a direction for meshing withsaid driving gear clutch teeth and allowing said clutch gear to bedisplaced axially away from said clutch gear if said clutch gear isrotated by said winding system in a direction opposite to a windingdirection for winding said winding mechanism, means on said winding stemto displace said clutch gear axially away from said winding gear againsta biasing force of said spring means when said winding stem is movedaxially to said second position thereof, and said means on said stemcomprising a portion having a diameter defining a shoulder for engagingsaid clutch gear.
 4. In a watch, a winding stem mounted for rotation forwind-ng a watch-winding mechanism in a winding first position andmovable axially to a hand-setting second position for rotation forsetting hand-setting mechanism, means mounting said winding stem forrotation and axial movement, said winding mechanism comprising a windinggear mounted for rotation about said winding stem and having peripheralteeth and ratchet teeth, a ratchet gear meshing with the peripheralteeth of said winding gear, a clutch gear mounted coaxially with saidwinding gear axially slidable on said winding stem for rotationtherewith, spring means constantly resiliently biasing the clutch gearaxially on said winding stem in a direction for meshing with saiddriving gear clutch teeth and allowing said clutch gear to be displacedaxially away from said clutch gear if said clutch gear is rotated bysaid winding system in a direction opposite to a winding direction forwinding said winding mechanism, means on said winding stem to displacesaid clutch gear axially away from said winding gear against a biasingforce of said spring means when said winding stem is moved axially tosaid second position thereof, and said means on said stem comprising acollar on said stem disposed on said stem for engaging said clutch gear.5. In a watch, a winding stem mounted for rotation for winding awatch-winding mechanism in a winding first position and movable axiallyto a hand-setting second position for rotation for setting hand-settingmechanism; means mounting said winding stem for rotation and axialmovement, said winding mechanism comprising a winding gear mounted forrotation about said winding stem and having peripheral teeth and ratchetteeth, a ratchet gear meshing with the peripheral teeth of said windinggear, a clutch gear mounted coaxially with said winding gear axiallyslidable on said winding stem for rotation therewith, spring meansconstantly resiliently biasing the clutch gear axially on said windingstem in a direction for meshing with said driving gear clutch teeth andallowing said clutch gear to be displaced axially away from said clutchgear if said clutch gear is rotated by said winding system in adirection opposite to a winding direction for winding said windingmechanism, means on said winding stem to displace said clutch gearaxially away from said winding gear against a biasing force of saidspring means when said winding stem is moved axially to said secondposition thereof, and said spring means comprising a spring housed insaid crown.